|My moss solution...|
I finally bought one large box of baking soda about a year and a half ago and got out on the roof of the garage. The two sentence tip really did not elaborate on how you used it: Must the surface be dry?, Should you dilute it with water? So I figured I would start with the one box and see what happened. A dry roof just seemed better from a safety perspective so I went out there on a dry day and just sprinkled the baking soda directly from the box. It certainly was not instant death, but the fact that it was no longer green was victory enough for me.
Since that initial experiment I have sprinkled baking soda on the remainder of my garage roof and, while I figure that I should probably go out there at some point and remove the black, dead bits, I am very happy with the result. I have had the moss regrow in only a couple of small spots, which I was quick to treat with the baking soda, and the rest just looks slimy during the rainy season and dried out in the summer. Emboldened by my rooftop success I decided I would try it on the lawn. The areas I tried out last year browned up quickly and have not regrown so I treated the rest of my backyard early this year. I have several mossy spots in the front yard as well, but as they do not receive much sunlight I have left them for the time being. I figure moss on the lawn is better than mud.
Before I published this post I went looking for a couple of other perspectives and found one article that suggested, since moss can be partly caused by excess shade, you trim your tree branches - not a happening thing at my house. I will take the tree branches over the lawn any day. I also found a comment on the UBC Botanical Garden Blog that cautioned against using the baking soda undiluted and near grass. I have not had a problem at all with the baking soda damaging my lawn. The only thing brown is the moss. I have noticed that if it does not rain the baking soda takes longer to do its job. A couple of times I have applied the baking soda just before a light rain and it does seem that the moss browns up faster once it gets wet.
In the interest of maintaining the work done by the baking soda I saw a suggestion that you rake the dead moss out and follow up with over seeding. A bit of compost would also likely help with the overall health of the lawn. I also thought that before I put up a post claiming that baking soda was an environmentally friendly way to kill moss that I should check and see if I could find anything about the subject. In that regard I found a blog posting from Green Living Tips that briefly describes the process of how baking soda is made. You can check it out and decide for yourself. Given the other options I saw of bleach, laundry detergent and zinc sulphate I am sticking with the baking soda.